In modern tire production, digital radioscopy has already been frequently used in non-destructive testing and thus belongs to the prior art due to prior public use.
In this respect, material testing is carried out in the form of sampling inspection, or material testing is directly incorporated into the production process. Particularly strict requirements are imposed on tire production which can consist of more than 200 different materials and is subject to high quality requirements.
The typical testing objective of x-ray testing mainly comprises detecting the symmetry of the inner tire structure. In this respect, the layer offset of individual belts, the steel cord layers and also the cord spacings in the carcass are examined. Furthermore, the tires are examined for bodies of air and foreign bodies or inclusions of flaws. In this respect, an x-ray image of the entire tire can be generated by rotation.
The ASTM Standard F-1035 is used, for example to qualify the image quality for radioscopic systems for tire testing. This standard uses a flat disc of a defined rubber mixture, in which a plurality of materials is introduced in specific structures and which can be respectively differentiated in the x-ray image.
DE 196 07 582 A1 discloses a method for monitoring an extruded strip. Here, x-rays are continuously or gradually passed through small regions of the strip transversely to the plane of the strip and the type, size, shape and/or distribution of the contaminants are detected inside the strip and also on the surface of the strip. If the contaminants exceed a predetermined threshold value, the dispersed system is excluded from being further processed.
DE 971 619 B discloses a system for wall inspection during the production of plastics tubes and pipes using radioactive radiators.
DE 101 60 398 B4 relates to a method for examining a matting, moved by a conveying means, of biomass particles, in particular of fibers or woodchips, for the production of chipboard. The biomass particles are spread by a spreading machine onto a forming belt. The precompressed matting then passes through an examining device, equipped with radiation sources, for radiographing the matting which is thus examined for foreign bodies such as metal parts or plastics parts. The forming belt is divided and, if a defect is found in the matting by the examining device, the belt can be moved apart with the formation of a gap so that the portion of the matting containing the defect is disposed of in a discharge shaft.
DE 10 2009 012 558 A1 relates to an examination device of a production machine of a filling plant. To exclude the presence of foreign bodies in the filled cans, the separated and packaged cans are examined by an x-ray examination device.
In practice, if a foreign body is detected in the material, the material feed is interrupted so that a portion of material which includes the foreign body or defects can be removed manually. The material feed and thereby the subsequent processing procedures of the material are interrupted thereby and additional start-up measures are required to continue the process.